One of the objectives of the pathologic examination of breast carcinoma tissue is to predict the future course of the disease and even to predict the form of therapy that will be effective. For many cases the prognosis is too general and the best therapy is unknown. The development of new tumor markers and the thorough testing of existing ones offer real promise for identifying reliable prognostic indicators; however, progress has been hindered by the lack of an adequate supply of tumor tissue from patients with known outcome. The availability of archived breast tumor tissue in paraffin blocks, combined with follow-up data on patients, would provide a significant clinical resource for tumor marker studies. The purpose of this project is to provide such a resource. We propose to establish the St.Louis Breast Tissue Registry, which will provide unstained paraffin sections, from well-defined subsets of breast carcinoma, to investigators who plan to study the prognostic significance of various tumor markers. The Registry will consist of a consortium of 1 private practice and 7 hospital-based groups who have agreed to pool their resources and create a registry of paraffin-embedded breast tumor specimens for which significant follow-up information exists. Pathologists at the collaborating institutions will supply the paraffin blocks, and their respective tumor registries will supply the follow-up data. We expect to collect and process for distribution to investigators a minimum of 8000 samples of breast cancer tissue. The tumor samples include 507 cases (estimated) of ductal carcinoma in-situ, and 2,535 cases (estimated) of node-negative breast carcinoma. All the information relating to the tumor specimens and patient follow-up will be entered into a computerized central database (using the Gemstone/Geode object-oriented database management system) located at the Washington University School of Medicine. The St. Louis Breast Tissue Registry will cooperate with similar registries in the United States and with the National Institutes of Health to form a consortium of registries with uniform policies and operations. We expect that the tumor marker data collected on specimens from these cases will significantly advance our ability to predict outcome and will lead to improved therapy for patients with breast cancer.